AIRCRAFT WITH VERTICAL TAKE-OFF AND LANDING-VTOL
The invention refers to a VTOL aircraft of the type that uses certain aerodynamic phenomena to increase the lifting force and to reduce the thrust/weight ratio. An aircraft 1 uses a propulsion system 2 consisting of four thrust producing elements, two in front 3 and two in rear 4. Each front thrust producing element 3 contains at least one front rotor 5 operated by at least one front electric motor, fixed on a fuselage 10. Each rear thrust producing element 4 contains at least one rear rotor 7 driven by at least a rear electric motor 8, fixed on the fuselage 10. On the fuselage 10 is attached symmetrically a front wing 12. On the fuselage 10 is attached symmetrically a rear wing 13. The wing 12 and 13 are used also in static conditions respectively in take-off and landing.
This application claims the benefit of U.S. Provisional Application No. 62/982,198, filed Feb. 27, 2020, which is hereby incorporated by reference in its entirety.
TECHNICAL FIELDThe invention refers to an aircraft with vertical take-off and landing—VTOL of the type that uses certain aerodynamic phenomena to increase the lifting force and to reduce the thrust/weight ratio.
BACKGROUNDNumerous efforts have been made to design an aircraft for vertical take-off and landing as in the patent application US 20170283048 A1. This aircraft uses different rotors for vertical and forward flight. As a result, during the forward flight phase, which duration is the longest, most electric motors are not used. This dead mass of the vertical lift electric motors increases the complexity and cost of the construction being not useful for 98% of the operation time of the aircraft.
A similar solution with the same disadvantages is described in the patent application U.S. Pat. No. 9,868,524 B2. In addition, the unprotected rotors can enter in contact with surrounding objects or with the people on the ground, which is a very dangerous behavior.
Others known solutions for aircraft with VTOL capability use tilting wings or tilting rotors. This type of aircraft requires a sophisticated control of the stability respectively of the relative position between the fuselage and the propulsion system that is realized by means of complex and expensive mechanisms. The control becomes even more difficult due to the change of the relative position between the center of pressure and the center of gravity of the aircraft especially during the transition period and due to the condition that the fuselage stays in a horizontal position all the time. Any mistake in this control can cause an undesirable accident. For example, if the pivoting mechanism is locked in the forward flight position, the aircraft can no longer land vertically.
Also, the majority of VTOL aircraft solutions use distributed electric propulsion (DEP) without however using additional aerodynamic phenomena to reduce the traction/weight ratio which in most cases is bigger than one (1.2-1.4).
Therefore, it is desirable for an aircraft to have an efficient flight both vertically and horizontally. It is also necessary that the speed of the aircraft be increased and the range extended. The aircraft must have a simple construction with a high level of redundancy. The rotors must be protected against contact with the material limitations of the surrounding space or with the persons on the ground.
ObjectivesThe main objective of the invention is to define a new architecture of a propulsion system and an aircraft with vertical take-off and landing that uses a single type of propulsion system for both horizontal and vertical flight and which produces lift even in static conditions.
Another objective of the invention is to reduce the weight of the embarked power sources.
Another objective of the invention is to achieve an aircraft with simplified construction, without actuators for wings, propellers or flaps, but which is fully operational.
Another objective of the invention is to protect the aircraft against the environment limitations.
Another objective of the invention is to avoid the contact of the rotors with the people on the ground.
Another objective of the invention is to increase the efficiency and the speed of the aircraft in forward flight.
Another objective of the invention is to offer a high redundancy level, without single points of failure that can conduct to a catastrophic event and can affect passenger integrity.
SUMMARYIt is an aspect of this disclosure herein to provide an improved aerial vehicle, having VTOL capability, in particular with respect to aerodynamic properties and/or maneuverability for cargo and passenger transportation.
The aerial vehicle according with this disclosure is represented by an aircraft with vertical take-off and landing that uses a propulsion system consisting of at least four thrust producing elements, respectively two at front and two at the rear. Each thrust producing element uses at least one rotor driven by at least one electric motor. The rotation plane of the front and rear rotors is considered to be substantially horizontal or slightly inclined when the aircraft is in a static/horizontally position. The electric motors are attached by means of some supports on both sides of a fuselage. On the front of the fuselage, a front wing is symmetrically attached. The front wing has an unmodifiable angle between 15° and 80°, measured when the aircraft is in a static position. On the rear of the fuselage, a rear wing is symmetrically attached. The rear wing has an unmodifiable angle between 15° and 80°, measured when the aircraft is in a static position. Both the front wing and the rear wing have two jet limiters at the ends. The front wing is positioned so that the rotational planes of the front rotors are located near the trailing edge of the front wing and above its upper surface. The rear wing is positioned so that the rotational planes of the rear rotors are located near the leading edge of the rear wing and below its lower surface.
In a first constructive variant, the diameters of the front rotors are equal with the diameters of the rear rotors.
In another constructive variant, the diameters of the front rotors are larger than the diameters of the rear rotors.
According to another aspect of the invention, a method of producing the vertical lift of the aircraft consists of acting the front rotors which produce a significant depression on the front wing and this contributes to increase the vertical thrust force. At the same time, the rear rotors are operated to produce an increased pressure on the rear wing lower surface and this contributes to increase of the vertical thrust force.
According to another aspect of the invention, a method of controlling the passage from vertical to forward flight and vice versa is achieved by varying the rotational speed of the rotors located at the rear compared with the rotational speed of the rotors located at the front, which causes the pitch angle change of the aircraft.
In various constructive variants the aircraft according to the invention can carry various load and passengers, or it can be used for aerial surveillance/imaging.
The aircraft according to the invention is a convenient and safe mean of transporting people and various loads between two locations without special infrastructure accommodations. As designed, the aircraft is stable in flight and has a compact size, so that the footprint on the ground and the required area of ground storage are minimal. The propulsion efficiency is improved in the vertical flight due to the component generated by the depression on the front wing and the increased pressure lower the rear wing exerted even under static conditions. The efficiency of the propulsion is improved in the forward flight due to the lift created by the front and rear wings. The lack of actuators for the propulsion system or for wings simplifies the construction and reduces the cost of the product.
Several examples of carrying out are described in relation with the
In a first embodiment, an aircraft 1, with vertical takeoff and landing, of a drone type, uses a propulsion system 2 consisting of four thrust producing elements, two in front 3 and two in rear 4 as in
In another embodiment several aircraft 1 structures are joined between jet limiters 4 and 5 forming together a compound structure 24, as shown in
In another embodiment, derived from shown in
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In another embodiment, an aircraft 80, of delivery type, uses a fuselage 81, having an enlarged volume 82, at the front and a reduced volume 83, at the rear, as shown in
In another embodiment derived from that
In another embodiment, a passenger aircraft 110, with vertical take-off and landing, uses a fuselage 111 which has a cabin 112, positioned in the center of gravity area, as is shown in
In another embodiment, an aircraft 140, of a drone type, uses several fuselages 141, more specifically three fuselages 141 in this example, which connect a front wing 142 with a rear wing 143, as shown in
In another embodiment, derived from that of
In another embodiment, an aircraft 160, designed mainly for delivery, uses four thrust producing elements, two in front 161 and two in rear 162, secured by two front supports 163 and respectively by two rear supports 164, as shown in
In another embodiment derived from that of the
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Each supplementary wing 206 has an airfoil profile aligned with the airfoil profile of the front and rear wings 201 and 202.
All the described variants can have curved wings as described in
All the described variants can have in an all-electric version a battery pack as power source for propulsion.
All the described variants can have in a hybrid-electric version a hybrid-electric power source for propulsion.
Any combination between the elements of this disclosure will be considered as being part of the description and of the claims.
Claims
1. An aerial vehicle of the type with vertical take-off and landing and/or of the type with ground effect, a vehicle that uses the same propulsion system for both vertical and horizontal flight, propulsion system powered either from a purely electric source, or from a hybrid unit wherein an aircraft (1) uses a propulsion system (2) consisting of at least four thrust producing elements, two in the front (3) and two in the rear (4), symmetrically arranged on both sides of the fuselage (10), and
- on the fuselage (10), at its front end is symmetrically attached a front wing (12), the front wing (12) being positioned at a fixed angle α between 15° and 80° with the horizontal plane when the aircraft (1) is in a static position, respectively at take-off/landing, and
- on the fuselage (10), at its rear end is symmetrically attached a rear wing (13), the rear wing (13) being positioned at a fixed angle α between 15° and 80° with the horizontal plane when the aircraft (1) is in a static position, respectively at take-off/landing, and
- the front wing (12) has at its ends two jet limiters (14), and
- the rear wing (13) has at its ends two jet limiters (15), and
- the front wing (12) has an airfoil profile that contains an upper surface (16), a lower surface (17), a leading edge (18) and a trailing edge (19), and
- the rear wing (13) has an airfoil profile that contains an upper surface (20), a lower surface (21), a leading edge (22) and a trailing edge (23), and
- the front and the rear thrust producing elements (3) and (4) are positioned on the fuselage (10) between the front wing (12) and the rear wing (13), and
- the airflow generated by the front and rear traction elements (3) and (4) on the front wing (12) and on the rear wing (21) creates an additional lifting force contributing to the vertical take-off process, even in static conditions.
2. The air vehicle of claim 1 wherein each front thrust producing element (3) contains at least one front rotor (5) driven by at least one front electric motor (6), and
- each rear thrust producing element (4) contains at least one rear rotor (7) driven by at least one rear electric motor (8), and
- the rotation plane of the front (5) and rear (7) rotors is considered substantially horizontal when the aircraft (1) is in a static position, respectively at take-off/landing, and
- the front wing (12) is positioned so that the rotation planes of the front rotors (5) are located in the vicinity of the trailing edge (19) of the front wing (12) and above the upper surface (17), and
- the rotational planes of the front rotors (5) is positioned in rapport with the front wing (12) at a fixed angle β between 110° and 160°, and
- the rear wing (13) is positioned so that the rotation planes of the rear rotors (7) are located near the leading edge (22) of the rear wing (13) and below the lower surface (20), and
- the rotational planes of the rear rotors (7) is positioned in rapport with the rear wing (13) at a fixed angle β between 110° and 160°.
3. The propulsion system of claim 1 wherein the propulsion system (2) produces a greater lifting force than the thrust force developed by the front and rear thrust producing elements (3) and (4).
4. A flight method which create an amplification of the vertical lift wherein in operation, during take off/landing of the aircraft (1), the front electric motors (6) activate the front rotors (5) producing an important depression on the upper surface (17) of the front wing (12) and this amplifies the vertical thrust force, and
- at the same time, the rear rotors (7) are operated, producing an increased pressure on the lower surface (20) of the rear wing (13) and this amplifies the vertical thrust force.
5. The method of claim 4, wherein the passage from the vertical flight to the horizontal flight of the aircraft (1) is carried out gradually during the transition period by varying the rotation speed of the rear rotors (7) with respect to the front rotors (5), producing the change of the pitch angle of the aircraft (1), and
- the rear rotors (7) are further accelerated until the front wing (12) and the rear wing (13) reach an optimal angle of attack and the aircraft (1) reaches the horizontal cruise speed, in which case the lift is mainly transferred to the front and rear wings (12) and (13).
6. The air vehicle of claim 2, wherein an aircraft (30), of the amphibious type, uses two main floats (31) attached symmetrically on both sides of a fuselage (32), and
- the main floats (31) have an elongated cylindrical shape,
- on the front and the rear of the electric motors (6) and (8) are attached some side floats (33), which are reduced in size compared to the main floats (31).
7. The air vehicle of claim 2, wherein an aircraft (40) uses front and rear wings (12) and (13) which are joined by means of connected straps (41), the connecting straps (41) providing additional protection to the front and rear rotors (5) and (7).
8. The air vehicle of claim 2, wherein an aircraft (50), designed for delivery, uses two elastic strings (51), attached on the fuselage (10) and above it, the two elastic strings (51) securing for transport of a packet (52), which may have different volumes.
9. The air vehicle of claim 2, wherein an aircraft (60), designed for delivery, has a compartment (61) attached below the fuselage (10), and
- on the fuselage (10) are attached some legs (62), supporting the landing, which have an aerodynamic profile, and
- various loads are stored in compartment (61) during transportation process.
10. The air vehicle of claim 9, wherein the aircraft (60) transports a parallelepipedic shape container beneath the fuselage (10).
11. The air vehicle of claim 2, wherein an aircraft (70), having rescue missions for injured or sick persons, has attached under the fuselage (10) a stretcher (71), and
- the stretcher (71) can carry an injured person (72), and
- the stretcher (71) slides on two guides (73) existent on the fuselage (10), and
- the stretcher (71) could contain the necessary equipment to support the life of the injured person (72).
12. The air vehicle as in claim 1, characterized in that an aircraft (80) uses a fuselage (81), having at the front an enlarged volume (82) and at the rear a reduced volume (83), and
- on the fuselage (81) a front wing (84) is fastened to the front side using two flattened supports (85), and
- the front wing (84) is distanced from the fuselage (81) so that the front air stream can flow between the front wing (84) and the fuselage (81), and
- on the fuselage (81) a rear wing (86) is fastened to the rear side using two flattened supports (87), and
- the rear wing (86) is distanced from the fuselage (81) so that the front air stream can flow between the rear wing (86) and the fuselage (81), and
- on the fuselage (81) are attached some thrust producing elements, two in the front (88) and two in the rear (89),
- the front thrust producing elements (88) are larger in diameter than the rear thrust producing elements (89).
13. The air vehicle of claim 12, wherein the aircraft (80) is designed for delivery, and the volume (82) contains an internal compartment (92), closed by a cover (93), and
- in the internal compartment (92) various loads are transported.
14. The air vehicle as in claim 12, characterized in that an aircraft (100), designed for air surveillance, has a multi-scanner (101) attached to the fuselage (81) on its front side, and the multi-scanner (101) contains a number of visual, acoustic and thermal sensors.
15. An operating method wherein, during the forward flight, the rear thrust producing elements (89) produce a depression on the upper surface of the fuselage (81), which decreases the drag.
16. The air vehicle of claim 1, wherein an aircraft (110), with vertical take-off and landing, designed for passenger transport, uses a fuselage (111) which has a cabin (112) positioned in the area of the center of gravity, and
- the cabin (112) can carry at least one passenger.
17. The air vehicle of claim 1, wherein several aircraft (1) are joined in the area between the jet limiters (4) and (5), forming together a compound structure (24), and the compound structure (24) is used to lift heavy loads.
18. The air vehicle of claim 1, wherein an aircraft (120), designed for various missions, has three pares (121) of thrust producing elements (122), all being attached, symmetrically, side by side from a fuselage (123), this configuration increasing the lift during the take-off and landing phases for heavier loads, and
- during forward flight a part of thrust producing elements (122) can be deactivated to increase the flight efficiency.
19. The air vehicle of claim 1, wherein an aircraft (130), designed for different missions, uses a third middle wing (131), located between the front thrust producing elements (3) and the rear thrust producing elements (4), and
- the middle wing (131) has an airfoil shape comprising a lower surface (132), an upper surface (133), a leading edge (134) and a trailing edge (135), and
- the middle wing (131) being positioned at a fixed angle α between 15° and 80° with the horizontal plane when the aircraft (130) is in a static position, respectively at take-off/landing, and
- the front thrust producing elements (3) create an increased pressure on the lower surface (132) and simultaneously the rear thrust producing elements (4) create a depression on the upper surface (133), and
- in forward flight the efficiency of the aircraft (130) is improved even at low speed of the aircraft (130) due to the forced air circulation around the middle wing (131).
20. The air vehicle of claim 1, wherein an aircraft (140), of a drone type, uses at least two fuselages (141) which connect a front wing (142) with a rear wing (143), and
- on each fuselage (141) are mounted using supports (144) two thrust producing elements, one in the front (145) and one in the rear (146).
21. The air vehicle of claim 20, wherein the aircraft (140) uses three fuselages (141), and during the forward flight, the front and rear thrust producing elements (145) and (146), located in the middle of the aircraft (140), can be deactivated to increase the flight efficiency.
22. The air vehicle of claim 1, wherein an aircraft (150), of a drone type, uses some front fuselages (151) which connect a front wing (152) with a middle wing (153), and
- the aircraft (150) uses some rear fuselages (154) which connect the middle wing (153) with a rear wing (155), and
- on each front fuselage (151) and on each rear fuselage (154) is mounted by a support (156) a thrust producing element (157), and
- the middle wing (153) improves the flight efficiency in both vertical and forward flight.
23. The air vehicle of claim 1, wherein an aircraft (160), designed mainly for delivery, uses four thrust producing elements, two in front (161) and two in rear (162), attached respectively in two front support (163) and in two rear supports (164), and
- the front supports (165) are attached by some arms (166) on a fuselage (167), and
- the rear supports (164) are attached on the fuselage (167) by some arms (168), and
- the fuselage (167) has an airfoil shape, and
- on each front support (163) is attached a plate (169), and
- on each rear support is attached a plate (170), and
- the two plates (169) sustain a front wing (171), and
- the two plates (170) sustain a rear wing (172), and
- the profile chord of the fuselage (167) is parallel with profile chords of the front and rear wings (171) and (172), and
- in forward flight the front and rear wings (171) and (172), respectively the fuselage (167) have the same angle of attack made with the frontal air flow.
24. The air vehicle of claim 23, wherein an aircraft (170), designed for aerial surveillance, has an aerodynamic fuselage (171), and in the top of the fuselage (171) is mounted a multi-scanner (172).
25. The air vehicle of claim 18, wherein an aircraft (180), designed for different missions, have a central fuselage (181), and
- on both sides of the fuselage (181) are located symmetrically two front rotors (184), two rear rotors (185) and two middle rotors (186), and
- the middle rotors (186) are more distanced from the fuselage (181) comparing with the front rotors (184) and the rear rotors (185), and
- the rotational plane of each middle rotor (186) is partially superimposed over the rotational planes of the corresponding front rotor (184) and rear rotor (185).
26. The air vehicle of claim 25, wherein an aircraft (190), which can transport at least one passenger, have a central fuselage (191), and bellow the fuselage (191) is attached a cabin (192), having an aerodynamic shape, and
- in take-off and landing the aircraft (190) is supported by two front legs (193) and by two rear legs (194), all being attached symmetrically on the cabin (192), and
- the front and rear legs (193) and (194) have an airfoil profile, aligned with the wing profiles, and
- the cabin (192) can transport one or more passengers seating on chairs which are inclined through the rear so that when the aircraft is in forward flight phase each chair has a substantially vertical position.
27. The air vehicle of claim 26, wherein the position of each chair can be adjusted by an actuator.
28. The air vehicle of claim 1, wherein an aircraft (200), of reconfigurable type, uses some front and rear wings (201) and (202) joined by means of connected straps (203), and
- the front wing (201) has at its ends some curved zones (204), oriented backwards and symmetrically disposed, which continue the airfoil profile of the front wing (201), and
- the rear wing (202) has at its ends some curved zones (205), oriented frontally and symmetrically disposed, which continue the airfoil profile of the rear wing (202).
29. The air vehicle of claim 28, wherein the aircraft (200) uses at least two supplementary wings (206) attached on the connected straps (203), and each supplementary wing (206) has an airfoil profile aligned with the airfoil profile of the front and rear wings (201) and (202).
Type: Application
Filed: Jan 26, 2021
Publication Date: Nov 25, 2021
Inventors: Liviu Grigorian GIURCA (Craiova), Michael Silviu SOIMAR (Norton Shores, MI)
Application Number: 17/158,833